Real-Time Illumination for Two-Level Volume Rendering

  • Andrew Corcoran
  • John Dingliana
Part of the Lecture Notes in Computer Science book series (LNCS, volume 7431)

Abstract

We propose improvements to real-time two-level rendering incorporating ray cast shadows and ambient occlusion of 3D volumetric datasets. Our ambient occlusion calculation utilises the same sampling scheme as standard per-voxel Phong shading thus allowing for an extremely computationally efficient rendering in comparison to other ambient occlusion algorithms. Our ray cast shadows technique requires no pre-processing, does not significantly increase memory requirements and is compatible with ray cast volume renderers. We validate these techniques through a number of user experiments. The results indicate that our ambient occlusion method increases the visual information in an image. Meanwhile, ray cast shadows appear to not provide the hypothesised improvement to image understanding, however this raises some interesting implications regarding the practical relevance of shadows in such two-level volume renderings.

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References

  1. 1.
    Svakhine, N., Ebert, D., Andrews, W.: Illustration-Inspired depth enhanced volumetric medical visualization. IEEE Transactions on Visualization and Computer Graphics 15, 77–86 (2009)CrossRefGoogle Scholar
  2. 2.
    Hauser, H., Mroz, L., Bischi, G.I., Groller, M.E.: Two-level volume rendering - fusing MIP and DVR. In: Proceedings of Visualization 2000, pp. 211–218. IEEE (2000)Google Scholar
  3. 3.
    Hauser, H., Mroz, L., Italo Bischi, G., Groller, M.: Two-level volume rendering. IEEE Transactions on Visualization and Computer Graphics 7, 242–252 (2001)CrossRefGoogle Scholar
  4. 4.
    Bruckner, S., Gröller, M.E., Mueller, K., Preim, B., Silver, D.: Illustrative Focus+Context approaches in interactive volume visualization. Scientific Visualization: Advanced Concepts (2010)Google Scholar
  5. 5.
    Nikolov, S.G., Jones, M.G., Agrafiotis, D., Bull, D.R., Canagarajah, C.N.: Focus+Context visualisation for fusion of volumetric medical images. In: Proceedings of the 4th International Conference on Information Fusion, Montreal, QC, Canada (2001)Google Scholar
  6. 6.
    Viola, I., Gröller, A.K.M.E., Kanitsar, A., Gröller, M.E.: Importance-Driven volume rendering. In: Proceedings of IEEE Visualization, pp. 139–145 (2004)Google Scholar
  7. 7.
    Preim, B., Tietjen, C., Dörge, C.: NPR, focussing and emphasis in medical visualizations. In: Simulation und Visualisierung, pp. 139–152 (2005)Google Scholar
  8. 8.
    Kim, Y., Varshney, A.: Saliency-guided enhancement for volume visualization. IEEE Transactions on Visualization and Computer Graphics 12, 925–932 (2006)CrossRefGoogle Scholar
  9. 9.
    Hadwiger, M., Berger, C., Hauser, H.: High-quality two-level volume rendering of segmented data sets on consumer graphics hardware. In: Visualization, VIS 2003, pp. 301–308. IEEE (2003)Google Scholar
  10. 10.
    Corcoran, A., Redmond, N., Dingliana, J.: Perceptual enhancement of two-level volume rendering. Computers & Graphics 34, 388–397 (2010)CrossRefGoogle Scholar
  11. 11.
    Levoy, M.: Display of surfaces from volume data. IEEE Computer Graphics and Applications 8, 29–37 (1988)CrossRefGoogle Scholar
  12. 12.
    Medina Puerta, A.: The power of shadows: shadow stereopsis. Journal of the Optical Society of America A 6, 309–311 (1989)CrossRefGoogle Scholar
  13. 13.
    Lindemann, F., Ropinski, T.: About the influence of illumination models on image comprehension in direct volume rendering. IEEE Transactions on Visualization and Computer Graphics 17, 1922–1931 (2011)CrossRefGoogle Scholar
  14. 14.
    Kniss, J., Premoze, S., Hansen, C., Shirley, P., McPherson, A.: A model for volume lighting and modeling. IEEE Transactions on Visualization and Computer Graphics 9, 150–162 (2003)CrossRefGoogle Scholar
  15. 15.
    Ropinski, T., Meyer-Spradow, J., Diepenbrock, S., Mensmann, J., Hinrichs, K.: Interactive volume rendering with dynamic ambient occlusion and color bleeding. Computer Graphics Forum 27, 567–576 (2008)CrossRefGoogle Scholar
  16. 16.
    Ropinski, T., Doring, C., Rezk-Salama, C.: Interactive volumetric lighting simulating scattering and shadowing. In: 2010 IEEE Pacific Visualization Symposium (PacificVis), pp. 169–176. IEEE (2010)Google Scholar
  17. 17.
    Kronander, J., Jönsson, D., Löw, J., Ljung, P., Ynnerman, A., Unger, J.: Efficient visibility encoding for dynamic illumination in direct volume rendering. IEEE Transactions on Visualization and Computer Graphics 99 (2011)Google Scholar
  18. 18.
    Sundén, E., Ynnerman, A., Ropinski, T.: Image plane sweep volume illumination. IEEE Transactions on Visualization and Computer Graphics 17, 2125–2134 (2011)CrossRefGoogle Scholar
  19. 19.
    Hadwiger, M., Sigg, C., Scharsach, H., Bühler, K., Gross, M.: Real-Time Ray-Casting and advanced shading of discrete isosurfaces. Computer Graphics Forum 24, 303–312 (2005)CrossRefGoogle Scholar
  20. 20.
    O’Shea, J.P., Banks, M.S., Agrawala, M.: The assumed light direction for perceiving shape from shading. In: Proceedings of the 5th Symposium on Applied Perception in Graphics and Visualization, APGV 2008, pp. 135–142. ACM, New York (2008)CrossRefGoogle Scholar
  21. 21.
    Sun, J., Perona, P.: Where is the sun? Nature Neuroscience 1, 183–184 (1998)CrossRefGoogle Scholar
  22. 22.
    Langer, M.S., Bülthoff, H.H.: Depth discrimination from shading under diffuse lighting. Perception 29, 649–660 (2000)CrossRefGoogle Scholar
  23. 23.
    Cole, F., Sanik, K., DeCarlo, D., Finkelstein, A., Funkhouser, T., Rusinkiewicz, S., Singh, M.: How well do line drawings depict shape? In: ACM SIGGRAPH 2009 Papers, pp. 1–9. ACM, New Orleans (2009)CrossRefGoogle Scholar
  24. 24.
    Šoltészová, V., Patel, D., Viola, I.: Chromatic shadows for improved perception. In: Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Non-Photorealistic Animation and Rendering, NPAR 2011, pp. 105–116. ACM, New York (2011)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Andrew Corcoran
    • 1
  • John Dingliana
    • 1
  1. 1.Trinity College DublinIreland

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